Implicit nothing type argument: handle nullable case properly

#KT-41620 Fixed

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsTestGenerated.java

@@ -13418,6 +13418,12 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                     runTest("compiler/testData/diagnostics/tests/inference/nothingType/generateConstraintWithInnerNothingType.kt");
                 }
 
+                @Test
+                @TestMetadata("genericOverride.kt")
+                public void testGenericOverride() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/nothingType/genericOverride.kt");
+                }
+
                 @Test
                 @TestMetadata("implicitInferenceTToFlexibleNothing.kt")
                 public void testImplicitInferenceTToFlexibleNothing() throws Exception {

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/checkers/ImplicitNothingAsTypeParameterCallChecker.kt

@@ -24,6 +24,7 @@ import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.TypeUtils
 import org.jetbrains.kotlin.types.typeUtil.isNothing
 import org.jetbrains.kotlin.types.typeUtil.isNothingOrNullableNothing
+import org.jetbrains.kotlin.types.typeUtil.isNullableNothing
 import org.jetbrains.kotlin.types.typeUtil.isTypeParameter
 
 object ImplicitNothingAsTypeParameterCallChecker : CallChecker {
@@ -61,10 +62,14 @@ object ImplicitNothingAsTypeParameterCallChecker : CallChecker {
             resolvedCall.candidateDescriptor.valueParameters.filter { it.type.isFunctionOrSuspendFunctionType }
                 .map { it.returnType?.arguments?.last()?.type }.toSet()
         val unsubstitutedReturnType = resultingDescriptor.original.returnType
-        val hasImplicitNothing = inferredReturnType?.isNothing() == true &&
+        val hasImplicitNothing = inferredReturnType?.isNothingOrNullableNothing() == true &&
                 unsubstitutedReturnType?.isTypeParameter() == true &&
                 (TypeUtils.noExpectedType(expectedType) || !expectedType.isNothing())
 
+        if (inferredReturnType?.isNullableNothing() == true && unsubstitutedReturnType?.isMarkedNullable == false) {
+            return false
+        }
+
         if (hasImplicitNothing && unsubstitutedReturnType !in lambdasFromArgumentsReturnTypes) {
             context.trace.reportDiagnosticOnceWrtDiagnosticFactoryList(
                 Errors.IMPLICIT_NOTHING_TYPE_ARGUMENT_IN_RETURN_POSITION.on(reportOn),

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/ExpressionCodegen.kt

@@ -1079,7 +1079,8 @@ class ExpressionCodegen(
         nestedTryWithoutFinally: MutableList<TryInfo> = arrayListOf(),
         stop: (LoopInfo) -> Boolean
     ): LoopInfo? {
-        return data.handleBlock {
+        @Suppress("RemoveExplicitTypeArguments")
+        return data.handleBlock<Nothing> {
             when {
                 it is TryWithFinallyInfo -> {
                     genFinallyBlock(it, null, endLabel, data, nestedTryWithoutFinally)

compiler/testData/diagnostics/tests/inference/nothingType/genericOverride.fir.kt

@@ -0,0 +1,12 @@
+interface A {
+    fun a(): A
+}
+
+fun error(s: String): Nothing = null!!
+
+class A1 : A {
+    override fun a() = test() ?: error("")
+
+    @Suppress("UNCHECKED_CAST")
+    private fun <V : A> test(): V? = this as? V
+}

compiler/testData/diagnostics/tests/inference/nothingType/genericOverride.kt

@@ -0,0 +1,12 @@
+interface A {
+    fun a(): A
+}
+
+fun error(s: String): Nothing = null!!
+
+class A1 : A {
+    override fun a() = <!IMPLICIT_NOTHING_TYPE_ARGUMENT_IN_RETURN_POSITION!>test<!>() ?: error("")
+
+    @Suppress("UNCHECKED_CAST")
+    private fun <V : A> test(): V? = this as? V
+}

compiler/testData/diagnostics/tests/inference/nothingType/genericOverride.txt

@@ -0,0 +1,19 @@
+package
+
+public fun error(/*0*/ s: kotlin.String): kotlin.Nothing
+
+public interface A {
+    public abstract fun a(): A
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class A1 : A {
+    public constructor A1()
+    public open override /*1*/ fun a(): kotlin.Nothing
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    @kotlin.Suppress(names = {"UNCHECKED_CAST"}) private final fun </*0*/ V : A> test(): V?
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/inference/nothingType/notEnoughInformationFromNullabilityConstraint.kt

@@ -10,7 +10,7 @@ fun test() {
         <!NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER{NI}, TYPE_INFERENCE_NO_INFORMATION_FOR_PARAMETER{OI}!>make<!>()
     )
 
-    select(make(), null)
+    select(<!IMPLICIT_NOTHING_TYPE_ARGUMENT_IN_RETURN_POSITION!>make<!>(), null)
 
-    <!TYPE_INFERENCE_FAILED_ON_SPECIAL_CONSTRUCT{OI}!>if<!> (true) <!TYPE_INFERENCE_EXPECTED_TYPE_MISMATCH{OI}!>make()<!> else TODO()
+    <!TYPE_INFERENCE_FAILED_ON_SPECIAL_CONSTRUCT{OI}!>if<!> (true) <!TYPE_INFERENCE_EXPECTED_TYPE_MISMATCH{OI}!><!IMPLICIT_NOTHING_TYPE_ARGUMENT_IN_RETURN_POSITION!>make<!>()<!> else TODO()
 }

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java

@@ -13424,6 +13424,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                     runTest("compiler/testData/diagnostics/tests/inference/nothingType/generateConstraintWithInnerNothingType.kt");
                 }
 
+                @Test
+                @TestMetadata("genericOverride.kt")
+                public void testGenericOverride() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/nothingType/genericOverride.kt");
+                }
+
                 @Test
                 @TestMetadata("implicitInferenceTToFlexibleNothing.kt")
                 public void testImplicitInferenceTToFlexibleNothing() throws Exception {

compiler/tests-spec/testData/diagnostics/notLinked/dfa/pos/52.kt

@@ -119,5 +119,5 @@ fun <T : <!FINAL_UPPER_BOUND!>String<!>> T?.case_11() = this
 fun case_11() {
     var x: Int? = 10
     x = null
-    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Int? & kotlin.Nothing?")!>x<!>.case_11()
+    <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Int? & kotlin.Nothing?")!>x<!>.<!IMPLICIT_NOTHING_TYPE_ARGUMENT_IN_RETURN_POSITION!>case_11<!>()
 }